Temperature-indicator.



Patented May 19, 1914.

Home@ E. R. MURRAY.

TEMPERATURE INDICATOR.

APPLIGATION FILED MAY 12. 1913.

UNI-TED STATES PATENT OFFICE.

vEDW'IN R. MURRAY, OFAALA'MEDA, CALIFORNIA.

i TEMPERATURE-INDICATOR.

Application led May 12, 1913. Serial No. 767,032.

Specicaton of Letters Patent.

Patented May 19, 1914.

Other objects and'advantages of the pres` vent invention will appear throughout the following specification and claims.

In thedrawingsz-Figure 1 is a side elevation of the thermometer and electrical circuit. Fig. 2 is a front view of the indicator boX. Fig. 3 is a fragmentary section of the thermometer tube.

` By referring to .the drawings it will be seen that 1 designates the thermometer which comprises an upper insulated section 2 composed of hard rubber or similar mate-' rial terminating atits top end in a curved neck`3, the end of which is open to the atmosphere. The lower section of the thermometer comprises a lass tube 4 which glass tube has one end tting in the bore 5 formedl in the'lower end of the rubber tube 2. The lower end of the tube 2 is somewhat enlar ed as indicated at 4a so as to constitute an e cient reinforcement lat the point where the glass tube fits into the rubber tube. This l glass tube 4 is preferably cemented in the lower end of the tube 2 so as to hold the glass tube.4 in firm engagement with `the Vrubbertube 2. The tube 4 isv provided withv a central bore 6 of the same diameter asVV the bore 5 of the tube 2, and it. will therefore, be seen that the mercury 7 may travel from the bore 6 into the .bore 5 and etliciently form a contact with the several contact'l wires hereinafter referred to.Y The tube 4 is formed so as to constitute a plurality-of bent or crooked portions 5, and the outer end of the tube 4 terminates in -an enlarged bulb 9 which constitutes'an air chamber for the tube 4. As stated, above, the main portion of the tube is lled with mercury 7 and a number of wires 9a are vulcanized into the tube 2 at points corresponding with the degres of heat desired to be indlcated. These wires project through the tube 2 to the bore 5 suliiciently to form an efficient contact with the mercury when the same rises within the tube2. The tube 2 is provided with a plurality of enlarged portions 10 around the apertures 11 through which the Wires 9Z1 pass so as to form an elficient gripping means for connecting the wires to the tube 2.

A number of electrom'agnetsv 12 are employedwhich are connected to the wires 9a, and these magnets operate indicating shutters 13 which shutters are placed in front of the magnets 12. Each of these shutters comprises a pivotal point 14 from which are radiated spokes 15, two of which spokes carry the indicating segment 16 and the other spoke carries the armaturesegment 17 adapted to be attractedby the magnet 12. The outer face of the segment 16 is colored so as to have half of its face the same color as the board 18 whereas the other half of the indicator segment is painted White bearing a number corresponding with the temperature on the thermometer indicated by the segment operating through the different contacts which register with the different points upon the tube 2. The indicating board 18 is provided with a plurality of slot-s 19 through which may be viewed the indicating segments to allow the temperature to be read. Of course, the colors used upon the segments should be in contrast to each other so as to allow the segments to b e easily reada at a distance. The armature 17 of eachv indicator is attracted by the core 2O of the magnets 12 so that when the lower end of the armature 17 is in contact with the core 20 the segment 16 has rotated on its pivotal point until the. gure -on the segment is seen through one of the slots 19 formed in the indicator'board or plate 18.. A second armature 21' is carried near the opposite end of each lmagnet and isadapted to be attracted thereby, which will -cause the arma-v ture 2l to break circuitwith the lead wire 22.` The opposite end of the'lead wire 22` is in turn connected to the ypivot point of the corresponding armature 21 ofl the succeeding magnet. The magnets 12 are, therefore,

'connected 'in series with the main lead-.23,

which main lead 23 Yis connected `to a batter); or other current furnishing means 24. The lead wire. 23 terminates ina knob 25 in the bottom of theloop of-the tube 4. If it is desired to run indicators on batteries of the closed circuit ty e, aresistance 26 1` s emplyed and may beplaced in the circuit by fioo' i comprising a pair of tubes, one of said tubes connecting the lead wires 27 to the wire 23 and to the armature 21 of the lowest magnet by the lead wire 28. When used in this manner, the current will iow from the batteries 24 through the wires 23 and 27, resistance 26, wire 28, through the armatures 2l, and wires 22 back to the batteries 24 through the wire 29 and those below it. The mercury 7 then rises in the tubes 2 and 5 until it touches one of the wires 9F. A circuit is then formed which actuates the indicating segment corresponding with the temperature reached. Vhen a circuit is closed through one of the magnets 12, all the lower magnets are cut out and the current passes through the armatures 21 of all magnets eXcept the one being actuated.

If it should be so desired, a bell 30 may be employed with any desired circuit, so that an audible signal is given to indicate some particular point of temperature.

What is claimed is l. A circuit closure of the class described formed of an insulated rubber and provided with a downwardly curved overhanging upper end, said overhanging upper end being open to allow the atmosphere to communicate with the interior of said insulated tube, a plurality of Contact wires vulcanized in said insulated tube, said insulated tube provided with an enlarged lower end having a socket formed therein, mercury in the other tube, said mercury containing tube having one end fitting in said socket and provided with a central bore, said insulated tube provided with a central bore of the same diameter as the bore in said mercury containing tube, said vmercury containing tube providedk with a plurality of crooked portions, said mercury containing tube provided lat its outer end with an enlarged bulb constituting an air chamber, and a contact wire secured tact wire extending into the tube throughv the lower bend,"an insulated tube having an enlarged socket at its lower end fitting over the transparent tube against the lower bend, the insulated tube having an upper down-turned end that is open to the atmosphere, contact wires extending into the insulated tube adjacent the end socket, and indicating means in circuit with the contact wires of the tubes. y

In testimony whereof I aiiX my signature in presence of two witnesses.

EDWIN R. MURRAY.

Witnesses:

FRANK N. CooLEY, S. C. LAW, Jr. 

